RE: Review of draft-ietf-tram-turn-server-discovery-08

"Tirumaleswar Reddy (tireddy)" <> Thu, 18 August 2016 05:21 UTC

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From: "Tirumaleswar Reddy (tireddy)" <>
To: Ralph Droms <>
Subject: RE: Review of draft-ietf-tram-turn-server-discovery-08
Thread-Topic: Review of draft-ietf-tram-turn-server-discovery-08
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From: Ralph Droms []
Sent: Thursday, August 18, 2016 6:34 AM
To: Tirumaleswar Reddy (tireddy) <>
Cc: Review Area Team <>;; IETF discussion list <>
Subject: Re: Review of draft-ietf-tram-turn-server-discovery-08

Tiru - thanks for advising me of your responses to the points in my review.

Do you and the other authors have any thoughts about my recommendations for section 5?

[TR] Agree with your recommendation, updated Section 5.


- Ralph

On Aug 17, 2016, at 11:24 AM 8/17/16, Tirumaleswar Reddy (tireddy) <<>> wrote:

Hi Ralph,

Thanks for the review. Please see inline.

-----Original Message-----
From: Ralph Droms []
Sent: Wednesday, August 10, 2016 2:58 AM
To: Review Area<> Team <<>>
Cc:<>; IETF discussion list
Subject: Review of draft-ietf-tram-turn-server-discovery-08

I am the assigned Gen-ART reviewer for this draft. The General Area Review
Team (Gen-ART) reviews all IETF documents being processed by the IESG for
the IETF Chair. Please resolve these comments along with any other Last Call
comments you may receive.

For more information, please see the FAQ at


Document: draft-ietf-tram-turn-server-discovery-08
Reviewer: Ralph Droms
Review Date: 2016-08-09
IETF LC End Date: 2016-08-11
IESG Telechat date: unknown


This draft is on the right track but has open issues, described in the review.

The draft is well-written and appears to be ready for publication, except as
noted below.

Major issues:

Section 5, DNS Service Discovery, includes more details about DNS Service
Discovery (DNS-SD) than is necessary for this specification.
While it can be useful to repeat some specific details of another specification
for, there is a danger in writing too many details that may not be entirely in
agreement with the published specification.  In the case of this document, I
suggest that section 5 be rewritten to just refer to DNS Service discovery, with
a minimum of explanation.
The example is useful ... although I think some of the details in the example
ought to be changed.  The use of DNS-SD over unicast DNS and multicast DNS
can be mentioned in a sentence somewhere in section 5, as the use of DNS-SD
is otherwise identical.  I would leave out section 5.1 altogether.

Looking at the IANA "Service Name and Transport Protocol Port Number
I see that TURN is registered as using service name "turn", rather than
"turnserver" as in the example.  Also in the example, the instance name
"<>" might be problematic, as the instance is usually just a single
label.  In fact, I interpret the text in the document to describe the instance
name as a single label.  It might be worth experimenting to see how DNS-SD
libraries deal with a label like "<>", or perhaps simply change
instance in the example to something like "exampleco TURN Server"

Changed to "exampleco TURN Server" and used service names "turn" and "turns".

Minor issues:

Section 5 mentions the use of a TXT record to carry additional information
about the TURN service instance.  Are there any conventions for the
name/value pairs carried in the TXT record?

No conventions.

If not, I think there should be a
note that any name/value pairs in the TXT record are left to local definition.

Okay, added following line:
The TXT record can contain any key/value pairs left to the local definition.

Editorial issues:

I suggest using the<> domain rather than local in the example for
clarity.  Perhaps also change the intro sentence for the example:

For example, TURN server advertises the following DNS records :
For example, the following DNS records would be used for a TURN server with
instance name "exampleco TURN Server" providing TURN service over UDP on
port 5030:


It would help readability if the columns in the DNS records in the example
could be lined up; something like (apologies if your mail reader changes the
column alignments and if I don't have the quoting right):

PTR "exampleco TURN Server"._turn._udp.local.

"exampleco TURN Server"._turn._udp.local.
SRV    0 0 5030 example-turn-server.local.


AAAA 2001:db8:8:4::2

Similarly, it would help readability if the list of DNS records for S-NAPTR
resolution were formatted in aligned columns.


In section 3, does "on top of" mean "in addition to" or "instead of"?

It means "in addition to".